EEZ H24005 Power Supply

by Envox

A fully open source programmable power supply with professional, lab-quality features and performance

View all updates Jul 11, 2019

The H24005 is Dead, Long Live the BB3!

Hi everyone,

After nearly two years on pause, we’d like to announce that we’ve given up on plans to continue production of the EEZ H24005. But we have not been on holiday! As some of you who contacted us already know, we’ve spent many hours trying to push the H24005 concept to the next level by addressing known issues and adding new features. From this effort was born EEZ Bench Box 3 (BB3)!

*The BB3 campaign will feature early-bird pricing. Subscribe now to make sure you are notified when it launches!*

BB3 addresses the following issues that we identified in the H24005:

  • More flexible. We found assembling and disassembling the H24005's front panel to be tedious and difficult. Its design limits modularity, as well, since it includes components that really belong to the modules themselves, rather than to the chassis (output terminals, switches, LED indicators, I/O ports, etc.). Each BB3 module will includes its own front panel, which will provide access to everything that needs to be exposed. We achieved an even greater level of modularity by splitting the digital control board (previously an Arduino Shield mounted on the enclosure's front panel) into two parts: a Microcontroller Unit (MCU) board and a backplane.
  • More powerful. The computing power and memory capacity required by the extensive functionality of the H24005's firmware pushes the Arduino Due to its limits. Its lack of "advanced" features like multitasking (by way of FreeRTOS, for example) make the Due unsuitable in other ways, as well. As a result, we decided to move to a more capable solution: the STM32F7. And, thanks to the improved modularity of BB3, it should be possible to choose some other MCU, SoC, or SBC as the main computing module in future releases.
  • More expandable. The H24005 only provided support for two modules; BB3 has the capacity to host up to three. (It is slightly taller but occupies exactly the same benchtop area.)
  • More readable. Screen size, resolution, and speed all depend on the display controller, and the STM32F7 is capable of driving a larger, higher resolution screen directly through an RGB interface. This also reduces the cost of the display and simplifies HMI programming. As a result, BB3 has a 4.3" (470 x 272) screen, compared to the 3.2" (320 x 240) screen of the H24005. It is more comfortable to use and better able to present information related to the attached modules. It is also more legible and better looking, in part because we can finally render fonts with anti-aliasing.

Main differences between BB3 and H24005

FeatureEEZ BB3EEZ H24005
Backplane for Peripheral ModulesYesNo
Max. Number of Modules / Power Outputs (Channels)3 / 62 / 2
MCU ModuleSTM32F7 MCU BoardArduino Shield r5B12
Power ModuleDCP405 power module or DCM220 dual power modulePower Board r5B12
OVP (Over-Voltage Protection)HW, fused (DCP405 only) / SWSW
Reverse Power Output ProtectionHigh power diode, fused (DCP405 only)TVS, not fused
No. of Power Relays for Output Couplings4 (Series, parallel, and split rail for first two modules; ground coupling for all modules)2 (Outputs in series and parallel)
Digital/Trigger Inputs21
Digital Outputs21
MCUSTM32F769IGT6Arduino Due
Flash Memory2 MB512 KB
Modules with On-Board EEPROM (for storing module specific params)YesNo
TFT Display4.3”3.2”
Rotary EncoderYes (Ø31 mm knob)Yes (Ø16 mm knob)
User Defined SwitchYesNo
Power Module CommunicationDedicated SPIShared SPI
Memory CardMicroSD (accessible from the front panel)SD (on the back of the TFT display)
Dedicated Fan ControllerYes, up to 2 fansNo
FanØ80 mm, 3- or 4-wireØ60 mm, 3-wire
Multi-Threaded FirmwareYesNo
Programmable Output ListsYes, low jitterYes
Synchronized OEYesNo
AC Input RangeFull range (115 / 230 V)115 / 230 V (manually switchable)
Dimensions290 (W) x 123 (H) x 240 (D) mm290 (W) x 84 (H) x 238 (D) mm

BB3’s modularity is further enhanced by the DIB (DIY Instrumentation Bus) specification, which will allow us to offer additional categories of Testing and Measurement (T&M) modules in the future. To begin with, the upcoming BB3 campaign will give you the option to choose between three different DIB compliant DC power modules. That’s up to six channels in a single box! Finally, we remain committed to a fully open source design, so all of our project files are available (and will be kept up-to-date) on our GitHub repository.

Thank you once again for all of your support and patience. We look forward to seeing you over on the BB3 campaign page very soon!


Denis & the Crowd Supply team

$123,234 raised

of $44,000 goal

280% Funded!
Not Available
Feb 23 2017
funded on



Envox d.o.o. is home of the Envox Experimental Zone (EEZ), an open source initiative to bridge the gap between DIY / hobbyist / educational / low-budget and professional / commercial test and measurement solutions.

Denis Kotlar (a.k.a. prasimix)

Project Manager

Martin Vladic

Senior Software Developer

OSH Park

Prototype PCB Manufacturer

ITEAD Studio


Production PCBA Manufacturer



Custom Enclosure Manufacturer

TME Electronic Components

Component provider

Würth Electronics eiSos GmbH & Co. KG


Component provider

See Also

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